Synthesis, characterization and antioxidant activity of selenium polysaccharide from Cordyceps militaris.

A purified selenium-containing derivatives of Cordyceps militaris polysaccharide synthesized using H2SeO3/HNO3 and BaCl2 as a catalyst was investigated in this paper. The reaction condition was optimized by selecting different reaction temperature and period. Afterward, the one with the highest Se content was purified by ultra-filtration device with a molecular cut off size of 10KDa. Followed by its structural characterizations. Results of IFR and 13C NMR spectroscopy indicated that C-6 substitution was predominant in selenized polysaccharide. The modified polysaccharide with molecular weight of 1998 KDa was mainly consisted of mannose, glucose and galactose in the mole ratios of with the mole ratios of 1:28.63:1.41. Thermogravimetric and morphological analyses of the samples were carried out by AFS, SEM and AFM. In addition, the in vitro antioxidant results suggested that selenium-containing polysaccharide should be applied as a novel selenium source in dietary supplements, with potent antioxidant properties.